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MPU6k: save 72 bytes of memory

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the buffer can be on the stack
This commit is contained in:
Andrew Tridgell 2012-09-18 13:56:52 +10:00
parent 37cb56f3e1
commit 7e544e8ead
1 changed files with 6 additions and 6 deletions
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12
libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp
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@ -199,7 +199,6 @@ static uint8_t _product_id;
// DMP related static variables
bool AP_InertialSensor_MPU6000::_dmp_initialised = false;
uint8_t AP_InertialSensor_MPU6000::_received_packet[DMP_FIFO_BUFFER_SIZE]; // FIFO packet buffer
uint8_t AP_InertialSensor_MPU6000::_fifoCountH; // high byte of number of elements in fifo buffer
uint8_t AP_InertialSensor_MPU6000::_fifoCountL; // low byte of number of elements in fifo buffer
Quaternion AP_InertialSensor_MPU6000::quaternion; // holds the 4 quaternions representing attitude taken directly from the DMP
@ -685,18 +684,19 @@ void AP_InertialSensor_MPU6000::FIFO_getPacket()
uint8_t i;
int16_t q_long[4];
uint8_t addr = MPUREG_FIFO_R_W | 0x80; // Set most significant bit to indicate a read
uint8_t received_packet[DMP_FIFO_BUFFER_SIZE]; // FIFO packet buffer
digitalWrite(_cs_pin, LOW); // enable the device
SPI.transfer(addr); // send address we want to read from
for(i = 0; i < _fifoCountL; i++) {
_received_packet[i] = SPI.transfer(0); // request value
received_packet[i] = SPI.transfer(0); // request value
}
digitalWrite(_cs_pin, HIGH); // disable device
// we are using 16 bits resolution
q_long[0] = (int16_t) ((((uint16_t) _received_packet[0]) << 8) + ((uint16_t) _received_packet[1]));
q_long[1] = (int16_t) ((((uint16_t) _received_packet[4]) << 8) + ((uint16_t) _received_packet[5]));
q_long[2] = (int16_t) ((((uint16_t) _received_packet[8]) << 8) + ((uint16_t) _received_packet[9]));
q_long[3] = (int16_t) ((((uint16_t) _received_packet[12]) << 8) + ((uint16_t) _received_packet[13]));
q_long[0] = (int16_t) ((((uint16_t) received_packet[0]) << 8) + ((uint16_t) received_packet[1]));
q_long[1] = (int16_t) ((((uint16_t) received_packet[4]) << 8) + ((uint16_t) received_packet[5]));
q_long[2] = (int16_t) ((((uint16_t) received_packet[8]) << 8) + ((uint16_t) received_packet[9]));
q_long[3] = (int16_t) ((((uint16_t) received_packet[12]) << 8) + ((uint16_t) received_packet[13]));
// Take care of sign
for (i = 0; i < 4; i++ ) {
if(q_long[i] > 32767) {